A ribbon cassette that accommodates an ink ribbon to be used in printing is well known in the art. A ribbon cassette described in Japanese Patent Publication No. 5625632, for example, includes a ribbon spool and a take-up spool that are rotatably supported in a cassette case. An ink ribbon is wound around the ribbon spool. The take-up spool draws the ink ribbon off the ribbon spool and takes up the ink ribbon that was used for printing characters and the like. A clutch spring is provided on a bottom end of the take-up spool. The clutch spring applies a rotational load to the take-up spool when an external force is applied to the take-up spool for rotating the spool in a direction opposite the direction in which ink ribbon is taken up. With this structure, a state in which suitable tension is applied on the ink ribbon is maintained.